Design of 3-D IIR filters via transformations of 2-D circularly symmetric rotated filters

A technique for the design of three-dimensional (3- D) filters is introduced in this paper. The design is based on coefficient transformations of two-dimensional (2-D) circularly symmetric filters. These filters can be designed by cascading 2-D rotated filters. The stability of the 3-D filters designed is discussed and a stabilization procedure based on cepstrum analysis, is proposed. Stable implementation schemes are introduced. Examples of spherically symmetric filters designed on the basis of the technique introduced are presented.